Shutter mechanism for cameras



Sept. 1944- c. E. JOHNSON 2,359,116

SHUTTER MECHANISM FOR CAMERAS Filed Sept. 23. 1940 3 Sheets-Sheet 1 Sept. 26, 1944. c, JOHNSON 2,359,116

' SHUTTER MECHANISM FOR CAMERAS Filed Sept. 23, 1940 3 Sheets-Sheet 2 5 lg 35 3/2 47 V 25 \l\ i k 59 f7zve71/7507" M i A Ziornegs Sept. 26, 1944. c. E. JOHNSON 2,359,116

SHUTTER MECHANISM FOR CAMERAS Filed Sept. 23. 1940 5 Sheets-Sheet 3 W I l [H I l AZZarn/egs Patented Sept. .26, 1944 UNITED STATES PATENT OFFICE Carl E. Johnson,

mesne assignments,

I4 Claims.

in direct relation to the operation of the magazine control mechanism of the camera.

A further object of the invention is to provide power operated shutter mechanism in combination with means for positively locking and periodically releasing the power mechanism and also means for alternately locking and releasing the shutter for actuation by the power mechanism.

These and other objects and advantages of the invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same parts throughout the views, and, in which:

Fig. 1 is a plan view of a lens mounting showing a pair of shutter leaves in open position in full lines and in closed position in dotted lines as well as a sectional portion of the shutter actuating mechanism taken approximately on line I--i of Fig. 2 with the upper section thereof removed.

Fig. 2 is a section taken approximatel on the line 2--2 of Fig. 1;

Fig. 3 is a plan view of the lens mounting and operating mechanism fully assembled; t

Fig. 4 is a section through the casing of the operating mechanism taken approximately on the line 44 of Fig. 2;

Fig. 5 is a section taken approximately on the line 5-5 of Fig. 4;

Fig. 6 is a section taken approximately on the line 6--6 of Fig. 4; i

Fig. '7 is a plan view of the tension indicator mechanism with the casing cover removed;

Fig. 8 is a plan view of a lens mounting showing a four leaf shutter and the means for connect ing the leaves for operation by the shutter operating cam member; and

Fig. 9 is a fragmentary view of a portion of the drive connections in Fig. 8 with an electrical drive substituted for the cam.

In Figs. 1 and 2 there is shown a pair of lens elements iii and II which are supported by lens mountings I2 and i3. These in turn are sup; ported by a wall l4 of the camera casing. A focusing ring I5 is shown and a clamp l6 secures the lens mountings to the camera casing I4. The inner lens mounting i3 is keyed as at I3a in Fig. 2 to the camera casing l4 to permit rectilinear St. Paul, Minn., assignor, by

to Mark Hurd Manufacturing Corporation, Minneapolis, Minn., a corporation of Minnesota Application September 23, 1940, Serial No. 357,935

sliding movement of the mounting relative to the camera casing.

A pair of shutter leaves ll are pivotally mounted at l8 and adapted to swing from the dotted closed position shown in Fig. 1 to the full line open position also shown in that figure. It will be seen that when the leaves are open their shape is such that they lie closely around the lens aperture and, that when they are snapped shut. they very quickly cover the aperture. Furthermore the shape of the leaves is such that there is movement inwardly toward the center of the aperture by portions of the leaves from nearly all directions at the same time. This provides an effective and quick acting shutter arrangement whichis of particular advantage when'used in connection with large lens elements.

Connected to each of the shutter leaf pivot shafts i8 are small cranks l9 and these cranks are connected b means of pivoted levers 20 to the cross head 2! of a slide block 22. The slide block 22*has an elongated aperture 23 formed therein to permit the block to move relative to a cam shaft 24. The cam shaft 24 carries a generally triangular cam 25 which is adapted to act against a pair of rollers 26 and 21, said rollers being carried by the slide block 22. The slide block 22 is slidably supported by a slide base 28.

The cam shaft 24 is mounted for rotary movement in a housing 29 and on said shaft is mounted a pair of ratchet cams 30 and 3|. Th cam 3i has teeth whose abutment faces face in a clockwise direction, and the cam 30 has teeth which face in a counterclockwise direction. A link 32 has its upper end connected at 33 with an auxiliary drive arm 34. Upward movement of the drive arm 34 will impart a counterclockwise rotational movement to the cam shaft 25. The driving cam 3| has a spring pressed ratchet 35 associated therewith to prevent movement of said cam in a reverse direction. The locking cam 30 has a dog 36 associated therewith which is adapted to abut the faces of teeth on said cam 30 to lock the shaft 24 against movement in its proper counterclockwise direction. The lower end of link 32 depresses the dog 36 when the drive arm 34 and link 32 are lowered to release the locking cam. If the link 32 and drive arm 34 are lifted the lower end of arm 32 will hold the locking dog 36 out of operative position until the cam shaft 24 is rotated to bring the dog out of locking relationship with said locking cam 3i.

A shaft 38 supports the drive arm 34 for movement therewith and on one end of the shaft 33 is mounted a spring motor 39. The drive arm 34 is provided with a pair of abutments 40 and 4i. The spring pressed dog 42 is adapted to engage one or the other of the abutments 4| to prevent and to limit rotational movement of the drive arm'34 under influence of the spring 33.

A lever 43 is also mounted on the shaft 38 for movement thereon and for movement relative to will encounter the drive arm 34 when said lever.

43 is swung in a clockwise direction. Lever 43 is connected by means of a lever 43 to a crank 43 mounted on the end of a shaft 50. said shaft being connected with the magazine control mechanism of the camera, said mechanism not being shown but being conventional and well known in the art. The spring motor 33 on its shaft '33 is connected by means of a worm gear and worm 32 to a winding shaft 33 which extends outwardly of the casing 34 and carries a knurled winding knob 53.

The casing 54 for the spring winding gears 3| and 52 also rotatably supports a pair of gears 53 and 31 which are connected by a crank pin unit 33 to the worm gear 5| for rotation therewith. As the winding shaft 33 is rotated to wind the spring 33 gears 33 and 31 will also rotate and suitable graduations on the face of gear 31 can be viewed through an aperture 53 in the face of casing 34. Thu it is impossible to determine the extent to which the spring 33 has been wound. The variation in spring tension is impotrant in controlling the speed of shutter operations which is necessary since different shutter speeds are required for different circumstances.

With the spring 33 wound to the desired degree of tension the shutter mechanism is in position for a cycle of shutter operation, The shutter leaves II are normally in the closed position indicated by dotted lines in Fig. 1. Upon actuation of the conventional magazine control mechanism the link 43 will first be moved to the right as viewed in Figs. 3 and 4 to depress the drive arm 34 and link 32 and release the dog 33 from engagement with the locking cam 33 on shaft 24. This also brings the spring pressed dog 32a into operative relationship behind one of the cam abutments on the driving cam 3|. When the magazine control mechanism actuates the link 43 to move it to the left as viewed in Figs. 3 and 4 the lever 43 on shaft 33 will swing in a counterclockwise direction until its cam member 44 contacts and releases the spring pressed dog 42 from the abutment 40 on the drive arm 34. At this point the spring 33 will snap the drive arm in a comterclockwise direction and bring the abutment 4| on the drive arm 34 into engagement with the spring dog 42. This, of course, snaps the link 32 upwardly and swings the operating cam 3| and shaft 24 in a counterclockwise direction. Thereupon the substantially triangular cam 23 on the shaft 24 will act against the roller 23 on the cross head 2| of the sliding block 22 and pull the block to the right. This will cause the crank members l3 on the, shutter leaf pivots l3 to snap to the right opening the shutter leaves to the full line position shown in Fig.1. The triangular cam 25 will rotate through an arc of approximately 120 degrees to bring a succeeding flat side to the position shown in Fig. 1, and the shutter leave will I consequently be snapped back to a closed position.

The drive arm 34 in Fig. 4 will be restored to the position shown therein by movement of the lever 43 to the right causing the pin I! to push the drive arm 34 around in a clockwisedirection until the spring dog 42 again engages the abutment 43 on the drive arm 34.

In Fig. 8 there is shown the adaptation of my shutter drive to a four leaf shutter as din'erentiated from the two leaf shutter described above. In Fig. 8 there is shown a lens mount 33 and the dotted line 3| indicates the lens aperture. An iris diaphragm is normally positioned between the rear lens element or elements carried by the mounting and the shutter unit by the diaphragm is omitted in the first described embodiment to clarify the showing of the shutter structure. The oll'set portion 32 at the right of the lens mounting 30 can be formed integrally with the mounting as shown rather than separately as in the other embodiment. The shaft 24 in Fig. 8 and generally triangular cam 23 are numbered the same as that shaft and cam in the first structure disclosed since they are identical and the lockingcams, drive cams, spring motor and the release and reset are the same as above. For

' that reason they are not shown in Fig. 8.

A bar 33 lies adjacent the triangular cam 25 and is provided with an elongated central aperture 34 to permit movement of the bar 33 relatlve to cam shaft 24. Bar 33 is provided with a pair of roller members 35 and 63, the former being mounted on the right-hand end of bar 33, and the roller 33 being mounted for rotation adjacent the left-hand end of the bar 33. The righthand end of this bar is pivotally connected to a lever 31 which has one end pivotally secured at 33. The left-hand end of the bar 33 is pivotally connected at 39 to a rocker arm 10 which in turn is pivoted at its center as at 1|. It will be noticed that the distance between the pivots 69 and H is the same as the length of the lever 31, and the width of the aperture 34 in the. bar 33 is greater than the diameter of the cam shaft 24 ,to permit the bar 33 to be rocked back and forth freely from its pivot points 33 and 1|.

The rocker arm 13 at its lower end is connected by a short link 12 to a crank 13 and said crank is also connected by a longer link 14 to a crank 13. The cranks l3 and 15 when moved are adaptcam shaft 24 actuates said shaft, the substantially triangular cam 23 will rotate against the roller 33 to swing the bar 33 to the right. This will move the rocker arm 13 in a counterclockwise direction on its pivot H. The lower end of the rocker arm 13 will swing the cranks 13 and 13 in a counterclockwise direction and similarly move the shutter leave 13 and H to bring them out of registration with the lens aperture 3|.

- Simultaneously the cranks l3 and 3| will in like I manner withdraw the shutter leaves 32 and 33 across the aperture 3| so that the lens aperture is completely uncovered, and as the cycle of shutter operation is completed through a degree movement of the cam 23 said cam will return to the position shown in Fig. 8 and cause the rocker arm 13 to act upon the cranks I3, 13, 13 and 3| larly advantageous for motion picture projectors,

to bring the shutter leaves together to a position indicated in e the operation of t e four leaf d descri 8. general principle of that of shutter with lenses of th an increase in is necessary that each leaf than would be require ameter'of lens arm on the pivot 1 links 12 and 1: which are adapted with the shutter crank have shown a erent form of drive from the type utilized in connection above described structures.

mech the movement for releasinfl resetting the shutter operation results shutter shown use camer due to the fact that shutter leaf poraway from and toward all directions about the center the quickly open and close to get the re eflec feature in comthe quick action of the spring conmeans pro nt even where the usually large'and considerable area and reoov I It should the shaft 24 times except cycle to prevent the shutter mechanism f bouncing and partially opening lensesand tions move from nearly desire bination with lens is unmust be extimes.

while I have shown and describedmy invention in connection with shutter mechanism for photographic cameras it should be understood that the invention is equally adaptable for usewith tu tests have shown that th mechanism ope xtremely high speeds with continuous so that it is equally adaptablefor use as High speed actuation is not a strobeonly smooth e shutter the lens center lens aperture, a power connection a ter including a shutter opening which prevents the mount fromtwisting relative This without twist be accurately maintained. structure once the lens is properly positioned with respect to a vertical line the lens mount can be moved inwardly or outwardly without disturbing this adiustment.

Itwill, of cou changes may be made in rangement and proportions without departin from the scope of my tion.

What is claimed is: a

1'. In a camera, a lens mounting having a lens aperture therein, a shutter leaf mounted for pivoted movement into and out of alignment with said lens aperture, a shutter actuating shaft connected to said shutter leaf, a rot be understood that various the form, details, ar-

of the various parts invenndln 1 8 first mentioned lever, ends of said levers, said shutter lying in and being movable in. a plane normal to the, axes of said shutter actuating and power transmitting shafts. 2. In a camera, a lensmounting having a lens aperture therein, shutter means arranged for movement into and out of alignment with said shutter means nection between said power including a pair outer swinging ends, being connected to said power deand the other of said levers .having a conlink pivotally levers, positions, ter lever and and sa d secon axis of said ends of said between position bei g with shutter lever and the pivots at the link nearly in alignment, and said said shutter lever and shutand closing dean opening and closing of said levers from their vice operable through cycle upon movement first ositi ment and connected to said shutter for actuating the latter, a latch releasably connected to said power operated means to hold it against movement, 0. lost motion connection between said latch and said shutter, a lock for releasably sec g said shutter, and said latch to secure said power operated means prior to securing of said shutter means 4. In a camera, a pivoted leaf shutter, a reciprocating member pivotally connected to said shutter to swina it (1 closed, rocating member havin a pair of fixedly s aced but the operation is exceedin ly quiet. 7 cam followersrthereon, a cam mounted between Attenti also called to the lens mount ad- I said followers and having high and low sides, a lustin ring II which can be rotated to bring high side being opposite a low side, the high sides the lens mount in or out with respect to the of said cambeing reduced at their outer portions,

c era and the key and means for rotating said cam. betweenthelensmountandtbecsmer GARLI- JOENI N.

link connecting th shutter operating move- 

